Pneumoscrotum with extensive subcutaneous emphysema in traumatic perineal injury: A case report

Key Clinical Message We present a rare case of pneumoscrotum with subsequent subcutaneous emphysema in penetrating perineal injury with a tangential wound. It is important to diagnose the underlying disease and treat the cause. An examination under anesthesia is crucial for the diagnosis and management of the set of injuries. Abstract Pneumoscrotum with subcutaneous emphysema in traumatic perineal injuries is an alarming sign and may indicate life‐threatening intraabdominal injuries or necrotizing fasciitis. We reported a case of pneumoscrotum and extensive subcutaneous emphysema of the abdomen and chest 2 days after admission. Pneumoscrotum was not seen on the initial Computerized tomographic scan.

pain.Primary survey was unremarkable showing stable vitals with no fever.Secondary survey revealed a Glasgow Coma Scale (GCS) of 15, good bilateral air entry, no external bruises or swelling.Abdomen was soft and non-tender.Bleeding from a lacerated wound in the perineum (5 × 3 cm) between the scrotum and the anal verge was noted and controlled with a compression dressing.The anal tone was normal.Proctoscopy revealed no mucosal damage or bleeding.The blood investigation for the trauma panel was normal.Pan computerized tomography (CT) scan of the head, neck, abdomen, and chest was unremarkable.Basic trauma panel laboratory tests were normal.Initial CT scans of the abdomen and pelvis were unremarkable.The patient was admitted to the surgical ward for pain control and perineal wound management.On admission, he was started on empirical antibiotic therapy (amoxicillin and metronidazole).
The patient did not have any respiratory or urinary tract symptoms, and urinary analysis was not requested.The patient's wound was washed with normal saline and packed with gauze wet to dry dressing.The patient was seen on the next day and the plan was to continue dressing with sitz bath.Two days after admission, local examination showed emphysema of the penis and the scrotal area extending to the abdomen and lower chest with a hissing sound.
The wound looked healthy, with no blebs or active bleeding.The patient was afebrile with no change in vital signs.The white blood cell range was normal.The patient was not complaining of any abdominal pain other than subcutaneous emphysema.On follow-up, his abdomen was soft, lax, non-tender, and chest examination was normal.
Repeat CT abdomen and pelvis with rectal and IV contrast were performed.Rectal contrast showed opacification of the large bowel with no obvious extraluminal contrast leak.CT abdomen revealed neither intraperitoneal air nor free fluid.Subcutaneous emphysema was seen in the penoscrotal area extending to the abdomen till the lower chest (Figures 1 and 2).No pneumothorax, F I G U R E 1 CT scan of chest, abdomen and pelvis showing subcutaneous emphysema.pneumomediastinum, or pneumoperitoneum was noted.
The patient was taken to the operating theater for wound exploration (Figure 3).Tangential wound in the lithotomy position at 1 o'clock position was seen with the last 3 cm of the wound extending under the skin piercing the dartos muscle (tunica dartos).Proctoscopy and sigmoidoscopy did not reveal any evidence of lower bowel injury of mucosa.Healthy fascia adherent with muscle, bleeding healthy tissues, and absence of any foul-smelling pus ruled out necrotizing fascia.
The wound was washed with hydrogen peroxide and closed with Vicryl 3/0 with a penrose soft drain to rule out blood collection or pus.Subcutaneous emphysema of abdomen and lower chest wall resolved by dissolving into the subcutaneous tissue.The drain was removed on the 3rd postoperative day.The patient was discharged home on the 6th day post-admission.Patient was seen in the outpatient clinic 8 days after discharge.Pneumoscrotum and subcutaneous emphysema resolved completely, and the perineal wound healed well.He returned to normal activity with no reported related problems during the follow-up visits up to 1 year.

| DISCUSSION
Most of the reported cases of pneumoscrotum in literature are due to direct trauma to the scrotum.Our case is unique due to its presentation as a perineal injury.The wound, however, was tangential, extending to the underlying dratos muscle where the air made its way to the scrotum.Therefore, we suggest proper examination of perineal wounds under general anesthesia.We present a rare case of pneumoscrotum with subsequent subcutaneous emphysema of the abdomen and chest that was missed on initial clinical evaluation after perineal injury.A prior case of an elderly patient with chronic non-healing scrotal wound presented with extensive emphysema and pneumoscrotum with bilateral pneumothorax which resolved after chest tube insertion, but the source of pneumothorax was not ascertained. 6n our case, the patient did not have a pneumothorax and the source of air was from the far-away wound.
Laceration of the scrotum with massive scrotal subcutaneous and retroperitoneal emphysema is reported in the literature with a wound size of 1.5 × 1.5 cm with a metallic foreign body.The wound was managed conservatively and not closed.The patient returned 5 days later with a massive bilateral scrotal and suprapubic subcutaneous emphysema. 7Our case did not show any retroperitoneal air on the CT scan.Akil et al reported an extensive subcutaneous emphysema secondary to perineal ulcer (3 × 3cm) and a pneumoscrotum that was treated conservatively. 8here are two ways for air to reach the scrotum.The first one, is direct air or gas introduced into the scrotum from outside.The second way is air inside the thoracic cavity travels along the layer of Scarpa and campers.These two-facia merge to form colles and dartos at the base of penis and scrotum, respectively.The air can travel from abdominal cavity to the abdominal wall by diffusion, then along the facial plane and into the scrotum.Subcutaneous emphysema and pneumoscrotum can easily be picked by x-ray in most cases.CT scan can detect underlying cause.Ultrasonography is helpful in detecting inflammation of epididymis and testis.Pneumoscrotum by itself is self-resolving but the underlying cause need to be diagnosed early and treated as it may lead to tension pneumothorax, bowel perforations or necrotizing fasciitis.Other causes are iatrogenic intervention. 4urthermore, diagnostic, and therapeutic colonoscopy or endoscopy has been associated with pneumoscrotum suggestive of bowel perforation. 9Mukendi presented a case of blunt trauma in a patient who was intubated, and chest tube was placed for suspected pneumothorax.On arrival to hospital, pneumoscrotum was noted which improved after replacing the chest tube. 10El Ellani et al presented a case of pneumoscrotum with pelvic fracture, scrotal and perineal laceration that was managed by fixation of fractures and Delbet drain. 11he management includes treatment of the underlying cause, extensive surgical emphysema may need an infraclavicular drain. 9While chest tubes and laparotomy and debridement of wound and antibiotic is as per the pathology.[12][13][14][15][16][17][18][19][20][21][22]

| CONCLUSION
Perineal trauma without pelvic fracture and anorectal injury may present with pneumoscrotum and extensive subcutaneous emphysema that could be benign condition.However, ruling out other serious causes by clinical examination and radiological investigation is needed to avoid unnecessary aggressive therapy.All perineal wounds should be examined under general anesthesia and sutured to avoid potential complications.

FUNDING INFORMATION
None.

CONFLICT OF INTEREST STATEMENT
The Authors declare that there is no conflict of interest.

DATA AVAILABILITY STATEMENT
Data used to support the findings of this case are included within the article.
T A B L E 1 literature review of concurrent traumatic pneumoscrotum diagnosed with CT scan.

Mechanism of injury Cause
Other site of subcutaneous emphysema Treatment Lostoridis et al. 13

F I G U R E 2
CT scan pelvis showing Pneumoscrotum.F I G U R E 3 Perineal wound after closure with drain.